ISAICP-9052: Move switch in private.

scripts/switch

+#!/usr/bin/env php
+<?php
+
+use Symfony\Component\Filesystem\Filesystem;
+
+include_once __DIR__ . '/../vendor/autoload.php';
+
+// Logs messages
+$log = function (string $type, string $message): void {
+  $message = trim($message);
+  print match($type) {
+    'info' => "\033[36m$message\033[0m",
+    'warning' => "\033[33m$message\033[0m",
+    'error' => "\033[31m$message\033[0m",
+  };
+  print "\n";
+  if ($type === 'error') {
+    exit(1);
+  }
+};
+
+[, $switch, $operation] = $argv;
+
+// Check command arguments.
+$errors = [];
+if (!in_array($switch, ['config-readonly', 'eu-oss-catalogue'])) {
+  $errors[] = "First argument should be 'config-readonly' or 'eu-oss-catalogue' but '$switch' given";
+}
+if (!in_array($operation, ['on', 'off'])) {
+  $errors[] = "Second argument should be 'on' or 'off' but '$operation' given";
+}
+if (($count = count($argv) -1 ) > 2) {
+  $errors[] = "This command only accepts 2 arguments but $count given";
+}
+if ($errors) {
+  $log('error', implode("\n", $errors));
+}
+
+$fileSystem = new Filesystem();
+$path = getenv('DRUPAL_PRIVATE_FILE_SYSTEM');
+
+if (empty($path)) {
+  $log('error', 'The DRUPAL_PRIVATE_FILE_SYSTEM environment variable is not set');
+}
+
+// Drupal expects the private filesystem path as relative to web root but in
+// CI/CD it might be set as absolute. Convert to absolute path.
+if (!$fileSystem->isAbsolutePath($path)) {
+  $dir = DRUPAL_ROOT . '/' . $path;
+  $path = realpath($dir);
+  if ($path === FALSE) {
+    $log('error', "The directory $dir doesn't exist");
+  }
+}
+
+$path .= '/killswitch';
+
+if (!$fileSystem->exists($path)) {
+  // Create the directory if it's missing.
+  $fileSystem->mkdir($path);
+  $fileSystem->chmod($path, 0770);
+}
+
+// File used as kill-switch.
+$killSwitch = "$path/disable-$switch";
+
+if ($operation === 'on') {
+  if ($fileSystem->exists($killSwitch)) {
+    $fileSystem->remove($killSwitch);
+  }
+
+  if ($switch === 'config-readonly' && getenv('CONFIG_READONLY') === 'false') {
+    $log('warning', "Config read-only is permanently disabled because the CONFIG_READONLY environment\nvariable is set to 'false'");
+  }
+  else {
+    $log('info', "The $switch functionality has been enabled");
+  }
+}
+elseif ($operation === 'off') {
+  $fileSystem->touch($killSwitch);
+  $log('info', "The $switch functionality has been disabled");
+}